Arterial Thickening and Atherosclerosis as seen on Carotid MRI in Patients with Primary Aldosteronism

Presentation Number: SAT-58
Date of Presentation: June 15th, 2013

Mitra Lynn Rauschecker*1, Christopher Tate Sibley2, Charalampos Lyssikatos3, Elena Belyavskaya4, Constantine A Stratakis3 and Smita Baid Abraham5
1NIH, Bethesda, MD, 2NIH/CC, Bethesda, MD, 3National Institutes of Health (NIH), Bethesda, MD, 4Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, 5Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD

Abstract

Background: Compared to patients with essential hypertension and healthy controls (HC), patients with primary aldosteronism (PA) demonstrate an increased rate of carotid wall thickening, as assessed by carotid intima-media thickness on ultrasound (1).  There are no studies, however, evaluating carotid wall volume, or the presence of lipid-rich cores, which can only be measured by carotid MRI, in patients with PA. Carotid MRI findings are reported to be highly correlated with atherosclerosis risk factors in asymptomatic subjects and were predictive of prior cardiovascular events in subjects undergoing carotid endarterectomy.  Compared with carotid ultrasound, carotid MRI has less user variability (2, 3).  In order to evaluate the degree of atherosclerosis in patients with PA, measurements of carotid wall volume (CWV) were obtained by MRI. We report three cases of PA in which carotid MRI revealed increased arterial wall thickness as compared with HC.

Methods: Patients were diagnosed with PA on the basis of an elevated aldosterone/plasma renin activity ratio (ARR) in conjunction with a positive confirmatory test. Participants underwent high resolution black blood carotid MR imaging at 3 Tesla using carotid coils, with semi-automated contouring to quantify wall volume. PA patients were compared with age-matched HC who had undergone carotid MRI at the NIH. CWV for the PA patients and HC were analyzed using an unpaired t-test.

Results: Mean CWV for the PA group (n=4) was 587.2 mm(95% confidence interval (CI) for the mean 393.6 to 780.8) while mean CWV for the HC group (n=4) was 469.9 (95% CI for the mean 418.1 to 521.6). The difference between the two groups was statistically significant (P<0.05).

Conclusion:  We demonstrate that patients with PA, compared to HC, have increased carotid artery thickness, which suggests an increased risk of atherosclerosis and cardiovascular events.

 

Nothing to Disclose: MLR, CTS, CL, EB, CAS, SBA